Girdel



c DORNIER GIRDER Filed June 28, 1920 1 ha. 6-215; f

fna'entor:

Patented Oct. 26, 1926.

PATENT OFFICE.

CLAUDIUS DORNIER, OF FRIEDBIGHSH AFEN, GERMANY.

GIBDETI.

Application filed June 28, 1920, Serial No. 392,550, and in Germany November 17, 1917.

(GRANTED UNDER THE PROVISIONS 'OF THE ACT OF IABCH 3, 1921', 41 STAT. L, 1313.)

My invention relates to girders and more especially to girders with triangular framework for use in connection with light forms of construction. For the purpose of combining light Weight with maximumpower of resistance against the possibility of the girder collapsing either along the vertical or theihorizontal plane, and further to prevent-any lateral shift, there are employed in accordance with my present invention both. for the flanges, as also for the web members, the grooves of which are essen tially uniform in shape and disposed in the longitudinal direction of the girders. At the assemblage points the -grooves engage one in the other.

Girders of the kind described will be found su erior to those hitherto in use by reason 0 their requiring but isolated rivet joints, ca able of being effected by simplest means. ince merely a small number of individual members are required, which may be made without trouble and joined with ease, the said girder will be also found eminently suitable for production on a large scale, without the exactitude of each individual girder being thereby in the least impaired. Oneparticular form of structure will prove specially suitable, in the case of which the sections of the flange and web members transversely to the longitudinal direction of the girder represent each a succession of alternately narrow and broad U- sha ed channels. For by. these means, even in the caseof larger widths of girder, it will be discovered that a relatively small number of channels will suffice for the purpose in hand, and these may therefore be obtained with all the more case and with every exacti- 'tude desired by a longitudinal rolling process.v

In the accompanying drawmg, forming a part of this specification, are shown by way of example and in a purely diagrammatic manner two forms of construction embodying the subject matter of my invention.

'In the drawings- Fig. l is a side elevation of a girder,

Fig. 2 a cross-section along the line 2-2 in Fig. 1,

gig. 3 a modified form of construction, an

Fi 4 a longitudinal section of the web members employed therein in stretched condition, as it presents itself before being applied to the flanges.

In the construction according to Figs. 1

and 2 the two flange plates A, B, as also the web member C are each provided with three narrow, upwardly bent, U-shaped'longitudinal grooves a, 6 0 each alternating with two broader downwardly bent grooves.

The dimensions are so chosen that the web member C as lon as it is in stretched condition, if placed etween the flange plates, would envelop with its grooves 0 the corresponding groovesb of the lower flange plate B, and, on the other hand, engage in the grooves a of the upper flange plate A, which member, by the way, is very thin. The member C, which as a whole is sinuously bent in a direction perpendicular to the centre plane of the plate, extends in zig-zag v fashlon as a triangular frame alternately Within the twoflange plates A and B, being riveted together with said plates at the' points of application and assemblage.

The modified form of construction according to Figs. 3 and 4 essentially differs from that above described merely by the fact of the web faces of the narrow U-shaped channels and the common flange faces of the web members being cut out at the points of intersection, in correspondence with the bendin angle of the grooves 0. As accordingly 0 y the faces 0 of the broad grooves continue their course unimpaired, the bending required to produce the sinuosity of the trellis work is very much facilitated. As Figs. 3 and 4 show, the indentures alternately differ somewhat among each other, this depending whether the released ends of two adjacent groove portions 0 when the webfaces c are bent back, are caused to approach (0)"or separate (0), in other words, whether they are to serve for a connection to the lower flange plate B or to the upper flange plate A. To prevent the web faces a from being fractured, the indentures are rounded ofl at the corners.

I wish it tobe understood that I do not desire "to be limited to the exact details of construction shown and described, for obv vious modifications will occur to a person skilled in the art.

I claim 1. A sheet metal trellis girder comprising two cords and a webmember extending zig-zag fashion between and fixed to said cords,'both said cords and said web member being formed with longitudinal corrugations, the corrugations of said Web member being fitted at the points of contact in corresponding corrugations of said cords.

2. A sheet metal trellis girder comprising two cords and a web member extending zig zag fashion between and fixed to said cords,

formed with longitudinalcorrugations, wide 7 corrugations alternating with narrow ones, the corrugations of said web member being fitted at the points of contact in corresponding corrugations of said cords.

In testimony whereof I aflix'my signature.

CLAUDIUS DORNIER. 

